Electric-circuit-testing device



S. G. BARNARD.

ELECTRIC CIRCUIT TESTING DEVICE.

APPLICATION FILED IUNE 8,1920.

1,382,884. Patented June 28, 1921.

2 SHEETSSHEET 1- any. 2

@3313 F1115 abtozmmj 's. G. BABNARD. ELECTRIC CIRCUIT TESTING DEVICE.

APPLICATION FILED JUNE 8,1920.

PatentedJune 28, 1921.

2 SHEETSSHEET 2.

563% 5/19 elf/ 501mm UNITED STATES sum EL G. BABNARD, OF SEATTLE, WASHINGTON, ASSIGNOR OF ONE-HALF DOTZER, 0F SEATTLE, WASHINGTON.

PATENT OFFICE.

TO HUGO ELnc'rnIc-cmcUn-rnsme nnvrcn.

Specification of Letters Patent.

Application filed June 8, 1920. Serial No. 387,386.

7 '0 all whom it may concern:

Be it known that I, SAMUEL G. BARNARD, a citizen of the United States, and resident of the cit of Seattle, county of King, and State of ashin n, have invented certain new and useful mprovements in Electric- Cireuit-Testing Devices, of which the following is a specification.

This invention relates to electric circuit testing devices, and more particularly to devices of that character for testing the efliciency of spark plugs and ignition coils; the principal object of the invention be1ng to provide a testing device which may be easily attached to or incorporated with the electrical equipment of motorvehicles or com-.

bustion engines ingeneral, withoutrequiring any substantial alteration in the same equipment, and which, in its construction, includes a movably mounted part comprising circuit closing contact members which provide for the closing of electric-circuits through the ignition system of the engine with that part in one position, but which provides the closing of electric circuits, through conducting members mounted on that part and wherein a spark plug may be placed, when the movable part is turned in another position, for the purpose of testing.

the eflioiency of the plug, or coils, etc.

Since it is apparent that devices of this character could be and necessarily would be made in a number of different styles and 'forms to adapt them to. the particularsysterm to which they were to be applied, the device here shown is intended only to be representative of devices of this character in eneral with the understanding that changes in form or arrangement necessary for the installation with circuit members of various characters could be made without departing from the spirit of the invention.

Another object of the invention is to provide testing devices of the above character that may be incorporated in the electrical system, or mounted as permanent fixtures in the ignition equipment of motor vehicles or engines or wh1ch may be made as independent, demountable devices for testing purposes in general.

In accomplishing these and other objects of theinvention, I have provided the improved details of constructlon, the preferred the line A-A of Fig. 5.

Patented June 28, 1921.

Fig. 7 is a diagrammatic view of a testing device adapted for use in connection with v brating coils, showing the circuit connections when the device is in what is termed running or off position.

F g. 8 1s a similar view of'thedevice in testing positlon, showing the circuits closed through the spark plug supports.

Figs. 9 and 10 .are views, respectively, slmllar to the views of Figs. 7 and 8, illustratingone representative arrangement of the testing device for use in connection with electr cal equlpments or ignition system of non-vibrator types.

Referr1ng more in detail to the several views of the drawings, wherein like reference numerals designate like parts: 1 and 2, respectively, designate supportin and movable swltch members, both of which may be formed of non-conductive material, such as porcelain, fiber, rubber, bakelite; the back or supporting member being provided at the upper and lower'corners at one side with contact screws 3 and 4, which serve. to support the device, as will presently be described, and which, at their outer ends, are equipped with heads which lie flush with the outer faceof the back member and serve not only as contact or circuit closing memhere but also as means for holding the device securely in place.

The upper corner of thesupporting member 1, opposite the corner carrying the screw 3, embodies a binding 0st 5 that is provided with means at its-'bac end for attaching a circuit, or so called ground wire, thereto and at its other end has a head ortion 6, which lies flush with the forward surface of the mem e similarly as do the heads of the ing member and terminating at a short dis- 7 screws 3 and Between the contacts, 3

and 5,. the switchmember 1 has 'a cut-out pocket 7 wherein a contact or plate 8 is disposed, said plate having an end 'portion'9 clamped beneath the head of screw 3 and an opposite end portion 10 turnedforwardly to extend'flush with the face of the support tance' from the binding post head 6.

The movable switch member 23lS pivotally mounted. on the member 1 by means of a post 12 that is fixed thereto, andextends revolubly through a central aperture in-the member 1. through the back end of the post or extension, and a spring washer 15 is placed between the key and member 1 to tension the blocks together sufii'ciently to hold them in any set or adjusted relation.

Mounted in the lower corner of the mom her 2 corresponding to the corner of member 1 which carries the screw 4:, is a binding post 18, provided atits outer end with means upperend portion 0 for attaching a circuit wire thereto and at its inner end with a head 19 that lies flush with the inner face of the movable-member and which is adapted to engage the screw 4 in a circuit closing contact when the member 2 is in one position, but, which is disengaged therefrom when the member 2 is turned about its pivot post.

Mounted, respectivel in the central and lower and upper spark plug holding members, 20 and 21, respectively; the member 20 comprisin a conductive metal strip that.

is extended t rough the member 2 and has its inner portion22 inlaid in the inner face wardly and laterally to the corner opposite the post 18 and its outer end extended at right angle fromthe block with a central strip 24. cut from and turned upwardly for a purpose presently described, leaving a slot 25 in the projecting portion.

The upper holding member 21 comprises a substantial U-shaped bracket with its base portion embedded in the movable member 2 except for a portion 26 which is exposed at the back of the plate to effect circuit closing connections with the post 5 when the plate is turned to testing position. The base of this bracket also has a pointed portion 28 turned outwardly therefrom to be'exposed A cotter key 14' is extendek the parts in this position, the inner end ofthe member 2 are of the member 2 and is extended .downat the outer face of the member 2 spacedfrom the end of the strip 24 to form a safet or spark gap of a desired or required widt for testing the efficiency of coils, etc.

Assuming that the testing device is so constructed and assembled, to attach the. 'same as a permanent fixture 1n connection with the ignition system of a certain type of vehicle, wherein the coil box of the ignition system is mounted on the dashboard of the i vehicle, as shown in Fig. 2, and'the terminal forward side of the dash with wires leading therefrom to the engine spark plugs'and the posts of its several coils areextended to the timing mechanism, the high tension wires.

(lower terminals) of any set of terminals is removed and the screw 4 applied-t0 the lower terminal and the screw 3 appliedto the upper terminal "of that set, without changing existing connections of the latter. The post to which the screw 3 is applied being the terminal ofa'primary winding and the post to which screw 4 applied being the terminal post of the secondary winding. The wire leading to the spark-plug is then attached For the purpose of testing the efliciency ofthe coils the switch member 2 'is moved pivotally on member 1 so that it will assume the position, as shown in Figs. 4 and 8; with the plate 22 contacts the head of the screw 4: and the base 26 of the bracket 21. brid es the head of the post-5 and plate 8,. whic is in electrical connection with screw 3. These connections established and the low tension circuit closed, will induce a high tension .current in the coil, which, to complete its circuit has to jump the gap'between the parts 24 and 28. The strengthand quality of the spark coil.

.105 indicates the elficiency and capacity of the For testing out spark-plugs the plug to be tested is placed in the bracket 21'and against support 20, as is shown in Fig. 4, the members 1 and 2 are moved into the same relative position as for testlng coils. A circuit through the device will then be closed through the plug and the spark jumping the gap between the spark plug points or electrodes will indicate the condition or efiiciency of the spark plug.

For using the device in connection with electrical e uipments or ignition systems of the non-vi rator type an interrupter, as shown at 50in Figs. 9 and 10, .is added to the device, incorporated, attached, or separate, and connected in series with the primary circuit to make and break the circuit,

as is required in testing.

What I claim as my invention is:

1.'The combination with an electric. circuit, of a circuit testing device, comprisin a body member whereon means is provided or supporting-a member to be tested, the said body member being movable to open or close a circuit through the supporting means.

2. A circuit testing device of the character described comprising relatively movableswitch members; one of which has circuit contact members thereon applicable to binding posts or terminals of an electric circuit, and means on the other member for supporting a spark plug, that are movable into circuit closln relation with the first named contact mem ers to close a circuit through the spark plug held'therein, for the purpose set forth.

3. A circuit testing device of the character described comprising relatively movable switch members; one of which has contact members thereon applicable to binding posts or terminals of an electric circuit, and the other of which has a circuit wire connection thereon and means for supporting a spark plug, and movable into positions to close a circuit through the circuit wire connection or through the spark plug supporting members, for the purpose set forth.

4. A circuit testing device of the character described, comprisin relatively movable switch members, one 0 which has contact members thereon applicable in circuit 0108- ing relation to contact points or terminals of an electric circuit, and the other of which has a circuit wire binding post thereon and spaced apart circuit closing members forming a sparking gap, movable with this member into positions to close a circuit through the circult wire binding post or into position to close a circuit through the spaced apart members to efi'ect a spark between the same.

5. A circuit testing device of the character described comprising a pair of pivotally joined switch blocks, one of which has contact members thereon applicable to binding posts or the like of an electric circuit and having a circuit wire binding post thereon, and the other of which has a circuit wire binding post thereon and spaced apart conductive members wherein a spark plug may be held in testing position, and said latter block being movable to one position to efiect the closing of a circuit through its circuit wire binding post and in another position to close a circuit through the said conductive members, for the pur ose set forth.

Signed at Seattle, ashington, this 29th day of May, 1920.

' SAMUEL ,G. BARNARD. 

